Strapping material is used in a wide variety of applications to secure or bundle loads. The strap material is typically metal or plastic and can be applied to the load using either a manual sealer or a powered sealer. Powered sealers can be pneumatic or electric and can be hand-held or machine-frame type machines. Non-powered (manual) sealers are typically hand-held or hand-operated tools.
The seals (for both metal and plastic strap) can be of the seal-less type or of the crimp seal type. In a seal-less seal or joint, the material is welded to itself (if plastic) or mechanically joined as by locking cuts and projections. Crimp seals, on the other hand, use a band that is bent or wrapped around overlapping portions of strap and mechanically crimped onto the strap. In such a joint, the seal is compressed onto the strap material and the strap material is deformed so as to be secured in the seal.
There are two principal types of seals that are configured based upon the size or width of the strap on which the seal is positioned. For both ½ and ⅝ inch strap, the seals are formed with a base portion and upstanding legs. A top portion of the seal extends from one of the legs, inwardly, forming an asymmetrical design. The legs are commonly referred to as a long leg (the leg that has the top portion of the seal extending therefrom) and a short leg (that leg that is only the upstanding side portion). For ¾ inch strap, the seal is symmetrical. That is, the top portion of the seal is formed from inwardly extending portions of both legs.
In many such seals, the seal is cut, at least in part and is urged into the material to create an interference type of fit. In this manner, portions of the strap and portions of the seal are forced from their respective bodies, into the other material. That is, the strap and seal are cut and bent into each other so that the materials are not only held by compression, but also by interference of the crimp seal with the strap “pulling” from the seal.
Known tools used to crimp the seal onto the strap are leverage-type (or lever-action) tools that include a pair of handles that are linked to jaws that pivot inwardly to compress the seal. The seal is held between the jaws and rests on an anvil surface of a shear. In such known tools, a set of jaws and shears are stacked to increase the area over which compression of the seal occurs and the number of locations at which the seal is crimped.
As with many such lever-action tools, in the open position (the crimp-receiving position), the tool tends to lock out. That is, there is a point in the pivot action after which the tool locks into the open position. At and beyond this lock-out position, manipulation of the tool is required to move the tool back toward the closed position.
When in the closed position (the seal-forming position), with a seal in the jaw, such known tools tend to urge to the open position due to the pivot location and configuration. This can result is poor and/or incomplete seal formation.
Moreover, such known tools are single-size tools. That is, the tool can only be used to form seals of a single size. As such, when different size seals are used, a separate tool is required for each seal size. For seal sizes of ½ and ⅝ inch (the asymmetrical seals), the jaw elements are also asymmetrical. One jaw element has an elongated blade that is designed to contact the long leg, while the other element has a shorter leg that is designed to contact the short leg. As such, the seal can only be positioned in the tool in one direction, or again, the result can be poor and/or incomplete seal formation.
Accordingly, there is a need for a front action seal tool for use with strap material. Desirably, such a tool is used to apply or install a high reliability crimp seal type of seal on overlapping strap material. Most desirably, such a tool applies or installs the crimp seal without damage to the underlying strap material. More desirably still, such a crimp seal is applied to the strap with minimal force, and includes features to prevent locking the tool out when fully open and premature opening when the tool is closed. Such a tool can be used with seals of different sizes, without having to change the jaw elements, and can be used with the seal at any position in the tool.